Relationship between relative solar radiation ratio and basal area at breast or forest floor height in planted forests of cedar and cypress

Abstract

Solar radiation under forest canopies were observed for 4 – 9 years in 9 observation plots in 3 forests of cedar and cypress with basal areas at breast height less than 46 m²ha^-1. 59 ratios of relative solar radiation calculated using these observed values will be published as research record along with values of basal area at breast or forest floor height. The difference of relative solar radiation ratios is not recognized clearly between the forests with increasing basal areas from new planted to young and closed canopy forests, and decreasing basal areas forests caused by thinning.